Bug: pre-processor ranges which should be empty are not

Dynare help (legacy posts)
1

The range 2:1 should be empty. Instead, the pre-processor treats it as equal to the range 1:2. This is a real problem for nested for loops, as in the snippet below.

Pre-processor input:

shocks;
	@#for index in 0:subdivisions
		var scripte@{index} = 1;

		@#for index2 in ( index + 1 ):subdivisions
			var scripte@{index}, scripte@{index2} = exp( -varrho * abs( @{index} - @{index2} ) / @{subdivisions} );
		@#endfor
	@#endfor
end;

Pre-processor output:

shocks;

@#line "dseg1.mod" 221
		var scripte0 = 1;


@#line "dseg1.mod" 224
			var scripte0, scripte1 = exp( -varrho * abs( 0 - 1 ) / 2 );

@#line "dseg1.mod" 224
			var scripte0, scripte2 = exp( -varrho * abs( 0 - 2 ) / 2 );

@#line "dseg1.mod" 226

@#line "dseg1.mod" 221
		var scripte1 = 1;


@#line "dseg1.mod" 224
			var scripte1, scripte2 = exp( -varrho * abs( 1 - 2 ) / 2 );

@#line "dseg1.mod" 226

@#line "dseg1.mod" 221
		var scripte2 = 1;


@#line "dseg1.mod" 224
			var scripte2, scripte2 = exp( -varrho * abs( 2 - 2 ) / 2 );

@#line "dseg1.mod" 224
			var scripte2, scripte3 = exp( -varrho * abs( 2 - 3 ) / 2 );

@#line "dseg1.mod" 226

@#line "dseg1.mod" 227
end;
2

Hi,

Thanks for reporting this. It will be fixed in the next release of Dynare, and is already fixed in the unstable version.

Best,